1. Field of the Invention
This invention relates generally to an arrangement for orienting an electric-operated fuel injector to an injector-receiving cup of a fuel manifold. The disclosed embodiment of the invention illustrates an arrangement for orienting a top-feed fuel injector to a cup of a fuel manifold using an orientation clip that is attached to the fuel injector and that includes a feature relating with a complementary feature of the cup to circumferentially locate the fuel injector about a center line of the cup and fuel injector while allowing the fuel injector, once circumferentially oriented, to position itself axially within the cup when being assembled to the fuel manifold.
2. Background Information
Spark-ignited, fuel-injected internal combustion engines enjoy extensive usage as the powerplants of automotive vehicles. Fuel is injected into an intake system of such an engine by electric-operated fuel injectors of a fuel manifold assembled to the engine. Such a manifold is also known as a fuel rail.
Various arrangements for the assembly and mechanical retention of an electric-operated fuel injector to and on a cup of a fuel manifold are shown in a number of patents, including U.S. Pat. Nos. 4,294,215; 4,307,693; 4,475,516; 4,823,754; 4,984,548; 4,993,390; 5,040,512; 5,074,269; 5,136,999; 5,680,845; and 5,724,946.
Certain fuel injectors inject fuel in a direction, or directions, that are other than along the fuel injector centerline. Such fuel injectors are sometimes called targeted fuel injectors. A split stream fuel injector is one example. When a targeted fuel injector is associated with an engine into which it injects fuel, the fuel injector should have a particular circumferential orientation about its centerline so that the direction(s) of fuel injection will be properly targeted. Improperly targeted fuel injectors may derogate engine performance and/or compliance with applicable vehicle standards.
Proper targeting of a fuel injector may also require proper axial positioning of the fuel injector. This can be accomplished by locating the fuel injector nozzle, which contains one or more metering orifices from which fuel is injected into an engine, in fixed geometric relation to a socket receptacle of the engine intake system into which the nozzle is inserted in a sealed manner. When a fuel manifold containing fuel injectors that have been properly circumferentially located in respective cups of the fuel manifold is assembled to an engine that has injector-receiving socket receptacles, the act of inserting the nozzles into properly sealed relationship with the socket receptacles can complete proper targeting of the fuel injectors.
A fuel manifold may comprise attachment features, apertured brackets for example, with which threaded fasteners are associated to fasten the fuel manifold to an engine. Once the fuel injector nozzles have seated in properly targeted positions in the socket receptacles, a need for further tightening of such fasteners in order to secure the fuel manifold on the engine may induce undesired stress, distortion and/or movement. For example, if fuel injector nozzles have been seated in properly targeted positions in respective socket receptacles in engine intake manifold runners before the manifold attachment fasteners have been fully torqued, the fuel manifold may distort in some way, and/or there may be some relative movement between some component parts, as the fasteners are finally tightened to full installation torque. With prevailing manufacturing procedures and dimensional tolerances of manufactured parts, it seems that the possibility of such distortion, or movement of component parts, at time of fuel manifold assembly to an engine, cannot be totally foreclosed in all circumstances.
It is known from one or more of the above patents to mechanically retain a fuel injector in a cup by a retention clip that constrains the two against any substantial movement, both circumferentially and axially. In certain circumstances, the presence of strict axial constraint may be undesirable from the standpoint of assembling a fuel manifold to an engine. For example, it is believed that strict axial constraint may contribute to undesired stress, distortion, and/or component part movement occurring during manifold assembly to an engine. Therefore, it is seen desirable to provide for fuel injector orientation relative to a cup which retains proper orientation for injector targeting purposes, but without such strict axial orientation that could result in, or aggravate, certain undesired effects when a manifold is assembled to an engine. A fuel manifold that incorporates such a capability may improve serviceability should it become necessary to remove the fuel manifold from an engine and thereafter re-install it.